Torsion balance



July 26, 1938. E. A. AHRNDT ET AL 2,124,968

TORSION BALANCE Filed May 29, 1935 INVENTORS EMIL ADOLFAHRNDT H ERMANUS WILHELMU5 GONDAGH ATTORNEYS Patented July 26, 1938 TORSION BALANCE Emil Adolf Ahrndt and Hermanus Wilhelmus Siindagh, Nijmegen, Netherlands, assignors to Naamlooze Vennootschap Vereenigde Draadfabrieken, Nijmegen, Netherlands Application May 29, 1935, Serial No. 24,014 In the Netherlands May 30, 1934 4 Claims. (Cl. 26559) This invention relates to torsion balances, and which is balanced by a counterweight I. On more particularly to balances of the type in the front clamp 2 a pointer 9 is attached, which which the balance beam, loaded with the article may be turned in the bearing 2a, together with to be weighed, is brought into the zero position the clamp 2, by means of the handle 8, whereby 5 by twisting a body, and in which the degree of the pointer is moved along the scale division it. 5

twisting or torsion of said body indicates the The rear clamp 2 may also be rotatably mounted Y weight of the article to be weighed. This torin the corresponding bearing 2a, thus serving sion, or the indicated weight respectively, may as a zero correction that is to say by means of be read from a scale provided with congruent said clamp the pointer 6 may be adjusted on 10 divisions. the zero point when the balance beam is released 10 The known balances of this type, which are from this clamp. usually applied for very small measuring ranges The balance as illustrated works as follows:

either are not sufficiently sensitive or they are, When the hook t is loaded with the article to in order to obtain the required sensitiveness, very be weighed, the shaft l is twisted, the hook sags complicated. Hence they are expensive and and the pointer 6 leaves the zero point to which 15 moreover only suitable for use in laboratories it was adjusted before the balance beam was but not adapted for continuous use in factories. loaded, By means of the handle 8 the torsion According to the invention a torsion balance is shaft is twisted to such a degree that the pointer obtained which is extremely sensitive and more- 6 is brought to the zero point. The deflection Over v y simp of design. The risk of breakof the pointer 9 thus obtained accurately indi- 20 downs is reduced to a minimum and the cost cates the weight on the scale l0.

price is reduced within reasonable limits. The Preferably the scale divisions are provided over balance is not only suitable for use in laborab t 180 to 250, As by the choice of the matories but for use in factories as Well. terial to be used for the torsion shaft, and of A c r to h i v n ion these features r its length and cross section it is possible to twist 25 obtained in such a way that the shaft on which t shaft by more th n 3 0 without exceeding t e balance beam is Supported Serves as a its limit of elasticity, the pointer 6 returns to 0 1 body at the same time. the zero point if the pointer 9 is brought back The balance or torsion shaft of the apparatus to th zero point, the hook being unloaded.

according t the tlon may consist of a It is easily possible to make the torsion shaft 30 p, a Wire, a plurality f the Sa of such dimensions that a deflection of the pointetm, Preferably d of me-terlal having 8 er 9 by 180 corresponds to a weight of 0.5 millihigh limit of elasticity, as tungsten, molybdenum, gram so that very accurately weighing is obsteel and like materials which have proved to mined.

give very satisfactory results. The torsion shaft Notwithstanding the great precision, a reading 35 however needs not to consist of metal but may may t k place in a considerably shorter time be made o e s, S gutstling, textile ads. than with a lever or beam balance of correspondetc. ing fineness, whereas the balance herein disclosed In order that the invent o ay be clearly has the advantage of greater accuracy and sim- 40 understood it will now be desc b With e pier construction as compared with torsion bal- 4o ence to the accompanying drawing, which diaoe known in the prior art. ramma i y s ws construction of a torsion It is to be noted that the invention has the adbalance made in accordance with the invention. vantage of being entirely free from mechanical The torsion shaft preferably sti f friction which might interfere with the sensitivea tungsten wire, is held at its ends in clamps 2 noes of th b lance, 45 which are located in bearin s a p ed n Whereasa certain embodiment of the invention the frame of the instrument (not s ow The has been described and illustrated, it is to be unbalance beam 3 is S cur d o the torsion Shaft derstood that modifications and changes in strucand is provided at one end with a hook 4 or the t may b made without departing from the like for carrying the art to Weighed and spirit of the invention as defined in the subjoined so at its other end with a thin, light plate 5 havlai ing a large surface perpendicular to the direcwhat i lai d 1 tion of mo e Serving for p g the 05- 1. An apparatus for indicating the weight of an cillations of the ba ance beam- Perpendicular article by the degree of torsion occurring in a torto the bale-nee be 3 Zero Pointer 5 is P v de sion body by the articles being weighed, said aphe paratus comprising in combination, a pair of clamps, one of said clamps being rotatable, means for rotating said clamp, a straight shaft of small cross section constituting the torsion body having its extremities directly secured in and to said clamps, a balanced rigid balance beam fixedly supported between the ends thereof upon said torsion body between the ends or the latter, said beam being adapted to be loaded at one end with the article to be weighed, means rigid with said balance beam indicating the zero position of the latter in unloaded condition, and means indicating the degree of torsion of the torsion body after returning the loaded balance beam to the zero position.

2. An apparatus for indicating the weight of an article by the degree of torsion occurring in a torsion body by the articles being weighed, said apparatus comprising, in combination, a pair of rotatably mounted spaced clamps, a straight shaft of small cross section constituting the torsion body which is directly fixed at its ends in and to said clamps, a balanced rigid balance beam secured between the ends thereof upon said torsion body between the extremities of the latter and provided at one end with means to support the article-to be weighed, means for rotating said clamps, means to fix one clamp independently of the other, means fixed to said balance beam to indicate the degree of torsion of the torsion body or the degree of rotation of the rotatable clamp with respect to the fixed clamp after returning the loaded balance beam to the zero position.

3. A torsion weighing scale comprising in combination, a pair of fixed spaced bearings, clamps rotatable therein, a straight torsion wire fixed axially at its respective ends directly to said clamps, a beam secured between its ends to said wire between the ends or the same wire, there being article supporting means at one end of said beam and a thin flat horizontally disposed plate at the opposite end, means on one 01' said clamps for rotating the same in either direction, an index finger fixed on the same clamp, an index scale graduated in terms of weight over which said finger may be moved, a balanced pointer fixed on said beam, and a zero indicator for the last named pointer.

4. A torsion weighing scale comprising in combination, a pair or alined bearings fixed in spaced relation, cylindrical clamps rotatable in said bearings, a straight torsion wire fixed at its ends in said clamps, a balanced beam rigidly secured between the'ends thereof to said wire between the ends of the letter, said beam having an article receiving means at one end and a gravity counterpoise at the other, a balanced vertical pointer carriedtby said beam, a stationary zero indicator therefor, an accurate index scale graduated to read in terms of weight, a second pointer fixed to one of said clamps to move relative to said index, and manual means secured to said pointer carrying clamp for rotating the same and bringing the first named pointer into registration with the zero position on said indicator, when the second named pointer indicates the weight of an article on said beam upon said index.

EMIL ADOLF AHRNDII. HERMANUS WILHELMUS S6NDAGH. 

